1. Field of the Invention
The present invention relates to a ballast for a discharge lamp, and more particularly to a ballast for a discharge lamp adapted to prevent a flicker effect and acoustic resonant phenomenon generated in the lighting of high voltage discharge lamp, such as a metal lamp, sodium lamp and the like.
2. Description of the Prior Art
When a discharge lamp is lighted and after the lamp is lighted in a conventional ballast for discharge lamp, there is a problem in that the voltage and a current difference are generated due to discharge and resonant frequency variation, resulting in acoustic resonant phenomenon and flicker effect.
Particularly, there is another problem in that a voltage or a current characteristic differs a little bit even in discharge lamps of identical design that one manufactured by the same company, and such difference frequently changes resonant frequency of the discharge lamps, and there is great difficulty in solving the acoustic resonant phenomenon and flicker effect.